Research

PKU professors make progress in photoelectron spin polarization

JAN . 29 2018
Peking University, Jan. 25, 2018: Recently, the research group at Peking University, Professor Liu Yunquan and Professor Gong Qihuang, performed a joint experimental and theoretical study on momentum- and energy-resolved photoelectron spin polarization in multiphoton ionization of Xe atoms by circularly polarized fields.

They have experimentally measured the three-dimensional photoelectron momentum distributions of Xe atoms in circularly polarized near-infrared (800 nm) and ultraviolet (400 nm) light, respectively. They analyzed the momentum- and energy-resolved photoelectron spin polarization by comparing the experimental photoelectron momentum distributions with the simulations based on strong-field approximation. It was shown that, in circularly polarized near-infrared light  at 800 nm the spin-up and spin-down electrons are inseparable and the overall photoelectron spin polarization is less than 40%, while in circularly polarized ultraviolet light at 400 nm the photoelectron spin polarization can be higher than 95% with momentum gating. This paves the way to produce high-degree spin-polarized photoelectrons from strong-field multiphoton ionization. This work was published on Physical Review Letters entitled with “Energy- and Momentum-resolved photoelectron spin polarization in multiphoton ionization of Xe by circularly polarized fields” (Phys. Rev. Lett. 120, 043201 (2018).

Edited by: Zhang Jiang
Source: School of Physics